mirror of
https://github.com/flutter/flutter.git
synced 2026-02-13 22:31:34 +08:00
e4ac518908
- Add Canvas.getSaveCount() - Make RenderClipRect call context.paintChildWithClip instead of doing the clipping itself - Make ClipLayer take a Rect instead of a Size - Make PaintingContext.canvas read-only - Add PaintingContext.paintChildWithClip() - Minor rearrangings of code and style tweaks
850 lines
28 KiB
Dart
850 lines
28 KiB
Dart
// Copyright 2015 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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import 'dart:math' as math;
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import 'dart:sky' as sky;
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import 'dart:sky' show Point, Offset, Size, Rect, Color, Paint, Path;
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import 'package:sky/base/debug.dart';
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import 'package:sky/base/hit_test.dart';
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import 'package:sky/base/node.dart';
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import 'package:sky/base/scheduler.dart' as scheduler;
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import 'package:sky/rendering/layer.dart';
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import 'package:vector_math/vector_math.dart';
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export 'dart:sky' show Point, Offset, Size, Rect, Color, Paint, Path;
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export 'package:sky/base/hit_test.dart' show EventDisposition, HitTestTarget, HitTestEntry, HitTestResult;
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class ParentData {
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void detach() {
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detachSiblings();
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}
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void detachSiblings() { } // workaround for lack of inter-class mixins in Dart
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void merge(ParentData other) {
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// override this in subclasses to merge in data from other into this
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assert(other.runtimeType == this.runtimeType);
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}
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String toString() => '<none>';
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}
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class PaintingCanvas extends sky.Canvas {
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PaintingCanvas(sky.PictureRecorder recorder, Rect bounds) : super(recorder, bounds);
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// TODO(ianh): Just use sky.Canvas everywhere instead
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}
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class PaintingContext {
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// A PaintingContext wraps a canvas, so that the canvas can be
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// hot-swapped whenever we need to start a new layer.
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// Don't keep a reference to the PaintingContext.canvas, since it
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// can change dynamically after any call to this object's methods.
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PaintingContext(Offset offest, Size size) {
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_startRecording(offest, size);
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}
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PaintingCanvas _canvas;
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PaintingCanvas get canvas => _canvas;
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PictureLayer _layer;
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PictureLayer get layer => _layer;
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sky.PictureRecorder _recorder;
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PaintingContext.forTesting(this._canvas);
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void _startRecording(Offset offset, Size size) {
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assert(_layer == null);
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assert(_recorder == null);
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assert(_canvas == null);
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_layer = new PictureLayer(offset: offset, size: size);
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_recorder = new sky.PictureRecorder();
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_canvas = new PaintingCanvas(_recorder, Point.origin & size);
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}
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void endRecording() {
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assert(_layer != null);
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assert(_recorder != null);
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assert(_canvas != null);
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_layer.picture = _recorder.endRecording();
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_layer = null;
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_recorder = null;
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_canvas = null;
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}
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bool debugCanPaintChild() {
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// You need to use layers if you are applying transforms, clips,
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// or similar, to a child. To do so, use the paintChildWith*()
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// methods below.
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// (commented out for now because we haven't ported everything yet)
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// assert(canvas.getSaveCount() == 1);
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return true;
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}
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void paintChild(RenderObject child, Point point) {
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assert(debugCanPaintChild());
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final Offset offset = point.toOffset();
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if (!child.requiresCompositing) {
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child._paintWithContext(this, offset);
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} else {
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_compositeChild(child, offset, layer.parent, layer.nextSibling);
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}
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}
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void paintChildWithClip(RenderObject child, Point point, Rect clipRect) {
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assert(debugCanPaintChild());
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final Offset offset = point.toOffset();
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if (!child.hasCompositedDescendant) {
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// If none of the descendants require compositing, then we don't
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// need to use a new layer here, because at no point will any of
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// the children introduce a new layer of their own.
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canvas.save();
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canvas.clipRect(clipRect.shift(offset));
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child._paintWithContext(this, offset);
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canvas.restore();
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} else {
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// At least one of the descendants requires compositing. We
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// therefore introduce a new layer to do the clipping, so that
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// when the children are split into a new layer, the clip is not
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// lost, as it would if we didn't introduce a new layer.
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ClipLayer clip = new ClipLayer(offset: offset, clipRect: clipRect);
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layer.parent.add(clip, before: layer.nextSibling);
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_compositeChild(child, Offset.zero, clip, null);
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}
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}
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void _compositeChild(RenderObject child, Offset offset, ContainerLayer parentLayer, Layer nextSibling) {
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final PictureLayer originalLayer = _layer;
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endRecording();
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Rect childBounds = child.paintBounds;
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Offset childOffset = childBounds.topLeft.toOffset();
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PaintingContext context = new PaintingContext(offset + childOffset, childBounds.size);
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parentLayer.add(context.layer, before: nextSibling);
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child._layer = context.layer;
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child._paintWithContext(context, -childOffset);
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_startRecording(originalLayer.offset, originalLayer.size);
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originalLayer.parent.add(layer, before: context.layer.nextSibling);
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context.endRecording();
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}
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}
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abstract class Constraints {
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const Constraints();
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bool get isTight;
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}
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typedef void RenderObjectVisitor(RenderObject child);
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typedef void LayoutCallback(Constraints constraints);
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abstract class RenderObject extends AbstractNode implements HitTestTarget {
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// LAYOUT
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// parentData is only for use by the RenderObject that actually lays this
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// node out, and any other nodes who happen to know exactly what
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// kind of node that is.
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dynamic parentData; // TODO(ianh): change the type of this back to ParentData once the analyzer is cleverer
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void setupParentData(RenderObject child) {
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// override this to setup .parentData correctly for your class
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assert(debugCanPerformMutations);
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if (child.parentData is! ParentData)
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child.parentData = new ParentData();
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}
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void adoptChild(RenderObject child) { // only for use by subclasses
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// call this whenever you decide a node is a child
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assert(debugCanPerformMutations);
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assert(child != null);
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setupParentData(child);
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super.adoptChild(child);
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markNeedsLayout();
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markNeedsCompositingUpdate();
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}
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void dropChild(RenderObject child) { // only for use by subclasses
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assert(debugCanPerformMutations);
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assert(child != null);
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assert(child.parentData != null);
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child._cleanRelayoutSubtreeRoot();
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child.parentData.detach();
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super.dropChild(child);
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markNeedsLayout();
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markNeedsCompositingUpdate();
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}
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// Override in subclasses with children and call the visitor for each child.
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void visitChildren(RenderObjectVisitor visitor) { }
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static bool _debugDoingLayout = false;
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static bool get debugDoingLayout => _debugDoingLayout;
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bool _debugDoingThisResize = false;
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bool get debugDoingThisResize => _debugDoingThisResize;
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bool _debugDoingThisLayout = false;
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bool get debugDoingThisLayout => _debugDoingThisLayout;
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static RenderObject _debugActiveLayout = null;
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static RenderObject get debugActiveLayout => _debugActiveLayout;
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bool _debugDoingThisLayoutWithCallback = false;
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bool _debugMutationsLocked = false;
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bool _debugCanParentUseSize;
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bool get debugCanParentUseSize => _debugCanParentUseSize;
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bool get debugCanPerformMutations {
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RenderObject node = this;
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while (true) {
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if (node._debugDoingThisLayoutWithCallback)
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return true;
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if (node._debugMutationsLocked)
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return false;
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if (node.parent is! RenderObject)
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return true;
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node = node.parent;
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}
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}
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static List<RenderObject> _nodesNeedingLayout = new List<RenderObject>();
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bool _needsLayout = true;
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bool get needsLayout => _needsLayout;
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RenderObject _relayoutSubtreeRoot;
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Constraints _constraints;
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Constraints get constraints => _constraints;
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bool debugDoesMeetConstraints(); // override this in a subclass to verify that your state matches the constraints object
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bool debugAncestorsAlreadyMarkedNeedsLayout() {
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if (_relayoutSubtreeRoot == null)
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return true; // we haven't yet done layout even once, so there's nothing for us to do
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RenderObject node = this;
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while (node != _relayoutSubtreeRoot) {
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assert(node._relayoutSubtreeRoot == _relayoutSubtreeRoot);
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assert(node.parent != null);
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node = node.parent as RenderObject;
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if (!node._needsLayout)
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return false;
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}
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assert(node._relayoutSubtreeRoot == node);
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return true;
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}
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void markNeedsLayout() {
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assert(debugCanPerformMutations);
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if (_needsLayout) {
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assert(debugAncestorsAlreadyMarkedNeedsLayout());
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return;
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}
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_needsLayout = true;
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assert(_relayoutSubtreeRoot != null);
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if (_relayoutSubtreeRoot != this) {
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final parent = this.parent; // TODO(ianh): Remove this once the analyzer is cleverer
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assert(parent is RenderObject);
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parent.markNeedsLayout();
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assert(parent == this.parent); // TODO(ianh): Remove this once the analyzer is cleverer
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} else {
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_nodesNeedingLayout.add(this);
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scheduler.ensureVisualUpdate();
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}
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}
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void _cleanRelayoutSubtreeRoot() {
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if (_relayoutSubtreeRoot != this) {
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_relayoutSubtreeRoot = null;
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_needsLayout = true;
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visitChildren((RenderObject child) {
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child._cleanRelayoutSubtreeRoot();
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});
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}
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}
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void scheduleInitialLayout() {
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assert(attached);
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assert(parent == null);
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assert(_relayoutSubtreeRoot == null);
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_relayoutSubtreeRoot = this;
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assert(() {
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_debugCanParentUseSize = false;
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return true;
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});
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_nodesNeedingLayout.add(this);
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scheduler.ensureVisualUpdate();
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}
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static void flushLayout() {
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sky.tracing.begin('RenderObject.flushLayout');
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_debugDoingLayout = true;
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try {
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List<RenderObject> dirtyNodes = _nodesNeedingLayout;
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_nodesNeedingLayout = new List<RenderObject>();
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dirtyNodes..sort((a, b) => a.depth - b.depth)..forEach((node) {
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if (node._needsLayout && node.attached)
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node.layoutWithoutResize();
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});
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} finally {
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_debugDoingLayout = false;
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sky.tracing.end('RenderObject.flushLayout');
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}
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}
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void layoutWithoutResize() {
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try {
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assert(_relayoutSubtreeRoot == this);
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RenderObject debugPreviousActiveLayout;
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assert(!_debugMutationsLocked);
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assert(!_debugDoingThisLayoutWithCallback);
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assert(_debugCanParentUseSize != null);
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assert(() {
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_debugMutationsLocked = true;
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_debugDoingThisLayout = true;
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debugPreviousActiveLayout = _debugActiveLayout;
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_debugActiveLayout = this;
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return true;
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});
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performLayout();
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assert(() {
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_debugActiveLayout = debugPreviousActiveLayout;
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_debugDoingThisLayout = false;
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_debugMutationsLocked = false;
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return true;
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});
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} catch (e) {
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print('Exception raised during layout:\n${e}\nContext:\n${this}');
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if (inDebugBuild)
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rethrow;
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return;
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}
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_needsLayout = false;
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markNeedsPaint();
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}
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void layout(Constraints constraints, { bool parentUsesSize: false }) {
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final parent = this.parent; // TODO(ianh): Remove this once the analyzer is cleverer
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RenderObject relayoutSubtreeRoot;
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if (!parentUsesSize || sizedByParent || constraints.isTight || parent is! RenderObject)
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relayoutSubtreeRoot = this;
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else
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relayoutSubtreeRoot = parent._relayoutSubtreeRoot;
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assert(parent == this.parent); // TODO(ianh): Remove this once the analyzer is cleverer
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if (!needsLayout && constraints == _constraints && relayoutSubtreeRoot == _relayoutSubtreeRoot)
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return;
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_constraints = constraints;
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_relayoutSubtreeRoot = relayoutSubtreeRoot;
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assert(!_debugMutationsLocked);
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assert(!_debugDoingThisLayoutWithCallback);
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assert(() {
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_debugMutationsLocked = true;
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_debugCanParentUseSize = parentUsesSize;
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return true;
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});
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if (sizedByParent) {
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assert(() { _debugDoingThisResize = true; return true; });
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performResize();
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assert(() { _debugDoingThisResize = false; return true; });
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}
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RenderObject debugPreviousActiveLayout;
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assert(() {
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_debugDoingThisLayout = true;
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debugPreviousActiveLayout = _debugActiveLayout;
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_debugActiveLayout = this;
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return true;
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});
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performLayout();
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assert(() {
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_debugActiveLayout = debugPreviousActiveLayout;
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_debugDoingThisLayout = false;
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_debugMutationsLocked = false;
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return true;
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});
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assert(debugDoesMeetConstraints());
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_needsLayout = false;
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markNeedsPaint();
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assert(parent == this.parent); // TODO(ianh): Remove this once the analyzer is cleverer
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}
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bool get sizedByParent => false; // return true if the constraints are the only input to the sizing algorithm (in particular, child nodes have no impact)
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void performResize(); // set the local dimensions, using only the constraints (only called if sizedByParent is true)
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void performLayout();
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// Override this to perform relayout without your parent's
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// involvement.
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//
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// This is called during layout. If sizedByParent is true, then
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// performLayout() should not change your dimensions, only do that
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// in performResize(). If sizedByParent is false, then set both
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// your dimensions and do your children's layout here.
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//
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// When calling layout() on your children, pass in
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// "parentUsesSize: true" if your size or layout is dependent on
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// your child's size or intrinsic dimensions.
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void invokeLayoutCallback(LayoutCallback callback) {
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assert(_debugMutationsLocked);
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assert(_debugDoingThisLayout);
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assert(!_debugDoingThisLayoutWithCallback);
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assert(() {
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_debugDoingThisLayoutWithCallback = true;
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return true;
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});
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callback(constraints);
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assert(() {
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_debugDoingThisLayoutWithCallback = false;
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return true;
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});
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}
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// when the parent has rotated (e.g. when the screen has been turned
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// 90 degrees), immediately prior to layout() being called for the
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// new dimensions, rotate() is called with the old and new angles.
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// The next time paint() is called, the coordinate space will have
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// been rotated N quarter-turns clockwise, where:
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// N = newAngle-oldAngle
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// ...but the rendering is expected to remain the same, pixel for
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// pixel, on the output device. Then, the layout() method or
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// equivalent will be invoked.
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void rotate({
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int oldAngle, // 0..3
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int newAngle, // 0..3
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Duration time
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}) { }
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// PAINTING
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static bool _debugDoingPaint = false;
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static bool get debugDoingPaint => _debugDoingPaint;
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static void set debugDoingPaint(bool value) {
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_debugDoingPaint = value;
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}
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bool _debugDoingThisPaint = false;
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bool get debugDoingThisPaint => _debugDoingThisPaint;
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static RenderObject _debugActivePaint = null;
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static RenderObject get debugActivePaint => _debugActivePaint;
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static List<RenderObject> _nodesNeedingPaint = new List<RenderObject>();
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PictureLayer _layer;
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PictureLayer get layer {
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assert(requiresCompositing);
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return _layer;
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}
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bool get requiresCompositing => false;
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bool _hasCompositedDescendant = false;
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bool get hasCompositedDescendant {
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assert(!_needsCompositingUpdate);
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return _hasCompositedDescendant;
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}
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bool _needsCompositingUpdate = false;
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void markNeedsCompositingUpdate() {
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if (_needsCompositingUpdate)
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return;
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_needsCompositingUpdate = true;
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final AbstractNode parent = this.parent;
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if (parent is RenderObject)
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parent.markNeedsCompositingUpdate();
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}
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void updateCompositing() {
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if (!_needsCompositingUpdate)
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return;
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visitChildren((RenderObject child) {
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child.updateCompositing();
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if (child.hasCompositedDescendant)
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_hasCompositedDescendant = true;
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});
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if (requiresCompositing)
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_hasCompositedDescendant = true;
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_needsCompositingUpdate = false;
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}
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bool _needsPaint = true;
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bool get needsPaint => _needsPaint;
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void markNeedsPaint() {
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assert(!debugDoingPaint);
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if (!attached) return; // Don't try painting things that aren't in the hierarchy
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if (_needsPaint) return;
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if (requiresCompositing) {
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_needsPaint = true;
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_nodesNeedingPaint.add(this);
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scheduler.ensureVisualUpdate();
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} else if (parent is! RenderObject) {
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// we're the root of the render tree (probably a RenderView)
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_needsPaint = true;
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scheduler.ensureVisualUpdate();
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} else {
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(parent as RenderObject).markNeedsPaint(); // TODO(ianh): remove the cast once the analyzer is cleverer
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}
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}
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static void flushPaint() {
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sky.tracing.begin('RenderObject.flushPaint');
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_debugDoingPaint = true;
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try {
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List<RenderObject> dirtyNodes = _nodesNeedingPaint;
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_nodesNeedingPaint = new List<RenderObject>();
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for (RenderObject node in dirtyNodes..sort((a, b) => a.depth - b.depth)) {
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if (node._needsPaint && node.attached)
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node._repaint();
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};
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assert(_nodesNeedingPaint.length == 0);
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} finally {
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_debugDoingPaint = false;
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sky.tracing.end('RenderObject.flushPaint');
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}
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}
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void _repaint() {
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assert(!_needsLayout);
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assert(requiresCompositing);
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assert(_layer != null);
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// TODO(abarth): Using _layer.offset isn't correct if the topLeft of our
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// paint bounds has changed since our last repaint.
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PaintingContext context = new PaintingContext(_layer.offset, paintBounds.size);
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_layer.parent.add(context.layer, before: _layer);
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_layer.detach();
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_layer = context._layer;
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_needsPaint = false;
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try {
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_paintWithContext(context, Offset.zero);
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} catch (e) {
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print('Exception raised during _repaint:\n${e}\nContext:\n${this}');
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if (inDebugBuild)
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rethrow;
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return;
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}
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assert(!_needsLayout); // check that the paint() method didn't mark us dirty again
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|
assert(!_needsPaint); // check that the paint() method didn't mark us dirty again
|
|
}
|
|
|
|
void _paintWithContext(PaintingContext context, Offset offset) {
|
|
_needsPaint = false;
|
|
assert(!_debugDoingThisPaint);
|
|
RenderObject debugLastActivePaint;
|
|
assert(() {
|
|
_debugDoingThisPaint = true;
|
|
debugLastActivePaint = _debugActivePaint;
|
|
_debugActivePaint = this;
|
|
debugPaint(context, offset);
|
|
if (debugPaintBoundsEnabled) {
|
|
context.canvas.save();
|
|
context.canvas.clipRect(paintBounds.shift(offset));
|
|
}
|
|
return true;
|
|
});
|
|
paint(context, offset);
|
|
assert(() {
|
|
if (debugPaintBoundsEnabled)
|
|
context.canvas.restore();
|
|
_debugActivePaint = debugLastActivePaint;
|
|
_debugDoingThisPaint = false;
|
|
return true;
|
|
});
|
|
assert(!_needsPaint);
|
|
}
|
|
|
|
Rect get paintBounds;
|
|
void debugPaint(PaintingContext context, Offset offset) { }
|
|
void paint(PaintingContext context, Offset offset) { }
|
|
|
|
void applyPaintTransform(Matrix4 transform) { }
|
|
|
|
|
|
// EVENTS
|
|
|
|
EventDisposition handleEvent(sky.Event event, HitTestEntry entry) {
|
|
// override this if you have a client, to hand it to the client
|
|
// override this if you want to do anything with the event
|
|
return EventDisposition.ignored;
|
|
}
|
|
|
|
|
|
// HIT TESTING
|
|
|
|
// RenderObject subclasses are expected to have a method like the
|
|
// following (with the signature being whatever passes for coordinates
|
|
// for this particular class):
|
|
// bool hitTest(HitTestResult result, { Point position }) {
|
|
// // If (x,y) is not inside this node, then return false. (You
|
|
// // can assume that the given coordinate is inside your
|
|
// // dimensions. You only need to check this if you're an
|
|
// // irregular shape, e.g. if you have a hole.)
|
|
// // Otherwise:
|
|
// // For each child that intersects x,y, in z-order starting from the top,
|
|
// // call hitTest() for that child, passing it /result/, and the coordinates
|
|
// // converted to the child's coordinate origin, and stop at the first child
|
|
// // that returns true.
|
|
// // Then, add yourself to /result/, and return true.
|
|
// }
|
|
// You must not add yourself to /result/ if you return false.
|
|
|
|
|
|
String toString([String prefix = '']) {
|
|
RenderObject debugPreviousActiveLayout = _debugActiveLayout;
|
|
_debugActiveLayout = null;
|
|
String header = '${runtimeType}';
|
|
if (_relayoutSubtreeRoot != null && _relayoutSubtreeRoot != this) {
|
|
int count = 1;
|
|
RenderObject target = parent;
|
|
while (target != null && target != _relayoutSubtreeRoot) {
|
|
target = target.parent as RenderObject;
|
|
count += 1;
|
|
}
|
|
header += ' relayoutSubtreeRoot=up$count';
|
|
}
|
|
if (_needsLayout)
|
|
header += ' NEEDS-LAYOUT';
|
|
if (!attached)
|
|
header += ' DETACHED';
|
|
prefix += ' ';
|
|
String result = '${header}\n${debugDescribeSettings(prefix)}${debugDescribeChildren(prefix)}';
|
|
_debugActiveLayout = debugPreviousActiveLayout;
|
|
return result;
|
|
}
|
|
String debugDescribeSettings(String prefix) => '${prefix}parentData: ${parentData}\n${prefix}constraints: ${constraints}\n';
|
|
String debugDescribeChildren(String prefix) => '';
|
|
|
|
}
|
|
|
|
double clamp({ double min: 0.0, double value: 0.0, double max: double.INFINITY }) {
|
|
assert(min != null);
|
|
assert(value != null);
|
|
assert(max != null);
|
|
return math.max(min, math.min(max, value));
|
|
}
|
|
|
|
|
|
// GENERIC MIXIN FOR RENDER NODES WITH ONE CHILD
|
|
|
|
abstract class RenderObjectWithChildMixin<ChildType extends RenderObject> implements RenderObject {
|
|
ChildType _child;
|
|
ChildType get child => _child;
|
|
void set child (ChildType value) {
|
|
if (_child != null)
|
|
dropChild(_child);
|
|
_child = value;
|
|
if (_child != null)
|
|
adoptChild(_child);
|
|
}
|
|
void attachChildren() {
|
|
if (_child != null)
|
|
_child.attach();
|
|
}
|
|
void detachChildren() {
|
|
if (_child != null)
|
|
_child.detach();
|
|
}
|
|
void visitChildren(RenderObjectVisitor visitor) {
|
|
if (_child != null)
|
|
visitor(_child);
|
|
}
|
|
String debugDescribeChildren(String prefix) {
|
|
if (child != null)
|
|
return '${prefix}child: ${child.toString(prefix)}';
|
|
return '';
|
|
}
|
|
}
|
|
|
|
|
|
// GENERIC MIXIN FOR RENDER NODES WITH A LIST OF CHILDREN
|
|
|
|
abstract class ContainerParentDataMixin<ChildType extends RenderObject> {
|
|
ChildType previousSibling;
|
|
ChildType nextSibling;
|
|
void detachSiblings() {
|
|
if (previousSibling != null) {
|
|
assert(previousSibling.parentData is ContainerParentDataMixin<ChildType>);
|
|
assert(previousSibling != this);
|
|
assert(previousSibling.parentData.nextSibling == this);
|
|
previousSibling.parentData.nextSibling = nextSibling;
|
|
}
|
|
if (nextSibling != null) {
|
|
assert(nextSibling.parentData is ContainerParentDataMixin<ChildType>);
|
|
assert(nextSibling != this);
|
|
assert(nextSibling.parentData.previousSibling == this);
|
|
nextSibling.parentData.previousSibling = previousSibling;
|
|
}
|
|
previousSibling = null;
|
|
nextSibling = null;
|
|
}
|
|
}
|
|
|
|
abstract class ContainerRenderObjectMixin<ChildType extends RenderObject, ParentDataType extends ContainerParentDataMixin<ChildType>> implements RenderObject {
|
|
|
|
bool _debugUltimatePreviousSiblingOf(ChildType child, { ChildType equals }) {
|
|
assert(child.parentData is ParentDataType);
|
|
while (child.parentData.previousSibling != null) {
|
|
assert(child.parentData.previousSibling != child);
|
|
child = child.parentData.previousSibling;
|
|
assert(child.parentData is ParentDataType);
|
|
}
|
|
return child == equals;
|
|
}
|
|
bool _debugUltimateNextSiblingOf(ChildType child, { ChildType equals }) {
|
|
assert(child.parentData is ParentDataType);
|
|
while (child.parentData.nextSibling != null) {
|
|
assert(child.parentData.nextSibling != child);
|
|
child = child.parentData.nextSibling;
|
|
assert(child.parentData is ParentDataType);
|
|
}
|
|
return child == equals;
|
|
}
|
|
|
|
int _childCount = 0;
|
|
int get childCount => _childCount;
|
|
|
|
ChildType _firstChild;
|
|
ChildType _lastChild;
|
|
void _addToChildList(ChildType child, { ChildType before }) {
|
|
assert(child.parentData is ParentDataType);
|
|
assert(child.parentData.nextSibling == null);
|
|
assert(child.parentData.previousSibling == null);
|
|
_childCount += 1;
|
|
assert(_childCount > 0);
|
|
if (before == null) {
|
|
// append at the end (_lastChild)
|
|
child.parentData.previousSibling = _lastChild;
|
|
if (_lastChild != null) {
|
|
assert(_lastChild.parentData is ParentDataType);
|
|
_lastChild.parentData.nextSibling = child;
|
|
}
|
|
_lastChild = child;
|
|
if (_firstChild == null)
|
|
_firstChild = child;
|
|
} else {
|
|
assert(_firstChild != null);
|
|
assert(_lastChild != null);
|
|
assert(_debugUltimatePreviousSiblingOf(before, equals: _firstChild));
|
|
assert(_debugUltimateNextSiblingOf(before, equals: _lastChild));
|
|
assert(before.parentData is ParentDataType);
|
|
if (before.parentData.previousSibling == null) {
|
|
// insert at the start (_firstChild); we'll end up with two or more children
|
|
assert(before == _firstChild);
|
|
child.parentData.nextSibling = before;
|
|
before.parentData.previousSibling = child;
|
|
_firstChild = child;
|
|
} else {
|
|
// insert in the middle; we'll end up with three or more children
|
|
// set up links from child to siblings
|
|
child.parentData.previousSibling = before.parentData.previousSibling;
|
|
child.parentData.nextSibling = before;
|
|
// set up links from siblings to child
|
|
assert(child.parentData.previousSibling.parentData is ParentDataType);
|
|
assert(child.parentData.nextSibling.parentData is ParentDataType);
|
|
child.parentData.previousSibling.parentData.nextSibling = child;
|
|
child.parentData.nextSibling.parentData.previousSibling = child;
|
|
assert(before.parentData.previousSibling == child);
|
|
}
|
|
}
|
|
}
|
|
void add(ChildType child, { ChildType before }) {
|
|
assert(child != this);
|
|
assert(before != this);
|
|
assert(child != before);
|
|
assert(child != _firstChild);
|
|
assert(child != _lastChild);
|
|
adoptChild(child);
|
|
_addToChildList(child, before: before);
|
|
}
|
|
void addAll(List<ChildType> children) {
|
|
if (children != null)
|
|
for (ChildType child in children)
|
|
add(child);
|
|
}
|
|
void _removeFromChildList(ChildType child) {
|
|
assert(child.parentData is ParentDataType);
|
|
assert(_debugUltimatePreviousSiblingOf(child, equals: _firstChild));
|
|
assert(_debugUltimateNextSiblingOf(child, equals: _lastChild));
|
|
assert(_childCount >= 0);
|
|
if (child.parentData.previousSibling == null) {
|
|
assert(_firstChild == child);
|
|
_firstChild = child.parentData.nextSibling;
|
|
} else {
|
|
assert(child.parentData.previousSibling.parentData is ParentDataType);
|
|
child.parentData.previousSibling.parentData.nextSibling = child.parentData.nextSibling;
|
|
}
|
|
if (child.parentData.nextSibling == null) {
|
|
assert(_lastChild == child);
|
|
_lastChild = child.parentData.previousSibling;
|
|
} else {
|
|
assert(child.parentData.nextSibling.parentData is ParentDataType);
|
|
child.parentData.nextSibling.parentData.previousSibling = child.parentData.previousSibling;
|
|
}
|
|
child.parentData.previousSibling = null;
|
|
child.parentData.nextSibling = null;
|
|
_childCount -= 1;
|
|
}
|
|
void remove(ChildType child) {
|
|
_removeFromChildList(child);
|
|
dropChild(child);
|
|
}
|
|
void removeAll() {
|
|
ChildType child = _firstChild;
|
|
while (child != null) {
|
|
assert(child.parentData is ParentDataType);
|
|
ChildType next = child.parentData.nextSibling;
|
|
child.parentData.previousSibling = null;
|
|
child.parentData.nextSibling = null;
|
|
dropChild(child);
|
|
child = next;
|
|
}
|
|
_firstChild = null;
|
|
_lastChild = null;
|
|
_childCount = 0;
|
|
}
|
|
void move(ChildType child, { ChildType before }) {
|
|
assert(child != this);
|
|
assert(before != this);
|
|
assert(child != before);
|
|
assert(child.parent == this);
|
|
assert(child.parentData is ParentDataType);
|
|
if (child.parentData.nextSibling == before)
|
|
return;
|
|
_removeFromChildList(child);
|
|
_addToChildList(child, before: before);
|
|
}
|
|
void redepthChildren() {
|
|
ChildType child = _firstChild;
|
|
while (child != null) {
|
|
redepthChild(child);
|
|
assert(child.parentData is ParentDataType);
|
|
child = child.parentData.nextSibling;
|
|
}
|
|
}
|
|
void attachChildren() {
|
|
ChildType child = _firstChild;
|
|
while (child != null) {
|
|
child.attach();
|
|
assert(child.parentData is ParentDataType);
|
|
child = child.parentData.nextSibling;
|
|
}
|
|
}
|
|
void detachChildren() {
|
|
ChildType child = _firstChild;
|
|
while (child != null) {
|
|
child.detach();
|
|
assert(child.parentData is ParentDataType);
|
|
child = child.parentData.nextSibling;
|
|
}
|
|
}
|
|
void visitChildren(RenderObjectVisitor visitor) {
|
|
ChildType child = _firstChild;
|
|
while (child != null) {
|
|
visitor(child);
|
|
assert(child.parentData is ParentDataType);
|
|
child = child.parentData.nextSibling;
|
|
}
|
|
}
|
|
|
|
ChildType get firstChild => _firstChild;
|
|
ChildType get lastChild => _lastChild;
|
|
ChildType childAfter(ChildType child) {
|
|
assert(child.parentData is ParentDataType);
|
|
return child.parentData.nextSibling;
|
|
}
|
|
|
|
String debugDescribeChildren(String prefix) {
|
|
String result = '';
|
|
int count = 1;
|
|
ChildType child = _firstChild;
|
|
while (child != null) {
|
|
result += '${prefix}child ${count}: ${child.toString(prefix)}';
|
|
count += 1;
|
|
child = child.parentData.nextSibling;
|
|
}
|
|
return result;
|
|
}
|
|
}
|